1. Field of the Invention
The present invention is related to a housing structure for a heat-dissipation fan and more particularly to the housing structure having a plurality of axial guide blades to form radial air inlets therebetween that air inflow is increased and air noise is reduced.
2. Description of the Related Art
Referring to FIG. 1, a conventional axial-flow type fan mainly includes a housing 10, a stator 20 and a rotor 30. The housing 10 is provided with an air inlet 11, an air outlet 12, a bearing seat 13 and a plurality of ribs 14. The stator 20 is fittingly connected to the bearing seat 13. The rotor 30 includes a hub 31 and blades 32 surrounding therearound; a shaft 33 is rotatably received in the stator 20 so that an alternative magnetic field generated by the stator 20 is able to rotate the rotor 30. When the blades 32 are rotated, air may be sucked into the housing 10 from the air inlet 11 and blown out of the housing 10 from the air outlet 12. The fan, has been widely used, is simplified for structure and manufacture, but it allows air inflow only sucked into the air inlet 11 that air inlet amount is limited by the measurements of the air inlet 11. Moreover, it is apparent that the rotations of the distal ends of the blades 32 may cause air turbulence and wind shear on the inner wall of the housing 10; airflow between the upstream and the downstream of the blades 32 may be unbalanced. Due to these drawbacks, the static pressure-flow rate characteristic (P-Q characteristic) of the fan is undesired.
Another conventional fan of U.S. Pat. No. 6,132,171, issued on Oct. 17, 2000, titled xe2x80x9ca blower and method for molding housing thereofxe2x80x9d discloses a fan housing with air inlet. A plurality of annular plates, proximate the air inlet, are equi-spaced and stacked to form radial annular gaps therebetween. When the blower is rotated, ambient air may be sucked into the housing through the annular gaps so that air inlet amount is increased. However, an additional airflow through the annular gaps is perpendicular to airflow through the air inlet that the convergence of the airflow may cause air turbulence and air noise. The P-Q characteristic of the blower is still undesired although it is provided with an additional air inlet amount. There is a need for the conventional housing to improve the P-Q characteristic.
The present invention intends to provide a housing structure for a heat-dissipation fan having axial guide blades which are equi-spaced to form radial air inlets therebetween. Airflow through the radial air inlets is guided parallel to an axis of the housing in such a way to mitigate and overcome the above problem.
The primary objective of this invention is to provide a housing structure for a heat-dissipation fan having axial guide blades, proximate an air inlet, adapted to form radial air inlets through which to guide airflow along an axis so as to increase air inlet amount and reduce air noise.
The secondary objective of this invention is to provide a housing structure for a heat-dissipation fan having inclined guide blades adapted to form radial air inlets and to face a rotational direction of the fan so as to increase air inlet amount and reduce air noise.
The another objective of this invention is to provide a housing structure for a heat-dissipation fan having an expanded air outlet shaped as a bell so as to increase measurements.
The another objective of this invention is to provide a housing structure for a heat-dissipation fan having axial guide blades made of metal so as to increase heat-dissipation efficiency.
The housing structure for the heat-dissipation fan in accordance with the present invention mainly comprises a housing, a plurality of axial guide blades and a plurality of radial air inlets. The housing is provided with an air inlet and an air outlet between which receiving a stator and a rotor. The axial guide blades are equi-spaced and radially extended outward from the housing proximate the air inlet. Each of the radial air inlets is formed between any two axial guide blades. When the rotor is rotated, airflow sucked through the radial air inlets is guided parallel to an axis of the housing running from the air inlet to the air outlet so as to increase air inlet amount and reduce air noise.